Heat loss analysis in the semi-buried anaerobic digester in Northeast Poland

Abstract

A thermal model was used to compare an actual and a computational heat losses in an existing the semi-buried anaerobic digester (AD) during the winter season in Northeast Poland. This work is an attempt to answer the question whether the cause of the temperature decrease of the manure AD is underestimated the heat exchanger or its low efficiency. The answer to this question is important for manager to take appropriate action. Understanding the heat loss of biogas digester is important to use these technologies to produce the biogas on assumed level in cold environment - like winter in Northeast Poland. From anaerobic digester point of view, the maintaining of optimal fermentation temperature is crucial. In the current study 2-D axisymmetric steady heat transfer model was carried out to calculate heat loss of AD for a real biogas plant located in north-eastern Poland and compared with actual state.